One of the types of negative tone photoresists is composed of at least a catalyst, a solvent, and epoxy resin. This is the primary raw material for lithography technology. To ensure high-quality pattern transfer in the lithography process, it is crucial to control the properties of the photoresist. In this work, a set of resins based on Bisphenol-A were synthesized. The obtained resins have been characterized regarding the chain size and its derivative products. As a second step, an epoxidation reaction was performed and the epoxy groups were quantified. The profile of the resins, obtained by mass spectroscopy (ESI-µ-TOF-MS), showed that it is possible to tune the chain sizes of the polymers and their derivate by controlling the parameters of the polymerization reaction. Three profiles of resins were achieved in this study. Nuclear magnetic resonance (NMR) indicates an epoxidation in the range of 96%, when comparing the phenolic peak intensity before and after the reaction. Differential Scan Calorimetry (DSC) measurements confirmed the different oligomer profiles of resins, showing different glass transition temperatures.

Different approaches of 2D lens arrays as Shack–Hartmann sensors for hard X-rays are compared. For the first time, a combination of Shack–Hartmann sensors for hard X-rays (SHSX) with a super-resolution imaging approach to perform multi-contrast imaging is demonstrated. A diamond lens is employed as a well known test object. The interleaving approach has great potential to overcome the 2D lens array limitation given by the two-photon polymerization lithography. Finally, the radiation damage induced by continuous exposure of an SHSX prototype with a white beam was studied showing a good performance of several hours. The shape modification and influence in the final image quality are presented.

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The characterization of negative photoresists before the application on LIGA process can be a key factor to save time, money and enhance the reproducibility of the main optical components fabricated to be used in techniques such as Talbot-Lau Interferometry.

Featured Application: The implementation of single-shot grating-based imaging within existing X-ray scanners will offer enhanced imaging contrast for weakly absorbing objects and materials with similar absorption cross-sections, profiting from phase and small-angle scattering contrasts. Due to the provided multi-modal information, such techniques can find broad applications in pre-clinical imaging of soft tissues, the determination of composite material structural orientation, and the visualization of formation processes of different natures, etc. To adapt the imaging modality to the intended application and profit from the versatility of those techniques, one requires customized optical elements. Our group has developed novel two-dimensional gratings, optimized for X-ray imaging at energies from 8 keV up to 25 keV, which can be used for orientation-independent inspection of materials within radiography setup.Abstract: Single-shot grating-based phase-contrast imaging techniques offer additional contrast modalities based on the refraction and scattering of X-rays in a robust and versatile configuration. The utilization of a single optical element is possible in such methods, allowing the shortening of the acquisition time and increasing flux efficiency. One of the ways to upgrade single-shot imaging techniques is to utilize customized optical components, such as two-dimensional (2D) X-ray gratings. In this contribution, we present the achievements in the development of 2D gratings with UV lithography and gold electroplating. Absorption gratings represented by periodic free-standing gold pillars with lateral structure sizes from 5 µm to 25 µm and heights from 5 µm to 28 µm have shown a high degree of periodicity and defect-free patterns. Grating performance was tested in a radiographic setup using a self-developed quality assessment algorithm based on the intensity distribution histograms. The algorithm allows the final user to estimate the suitability of a specific grating to be used in a particular setup.

High time resolution in scattering analysis of thin films allows for determination of thermal conductivity by transient pump-probe detection of dissipation of laser-induced heating, TDXTS. We describe an approach that analyses the picosecond-resolved lattice parameter reaction of a gold transducer layer on pulsed laser heating to determine the thermal conductivity of layered structures below the transducer. A detailed modeling of the cooling kinetics by a Laplace-domain approach allows for discerning effects of conductivity and thermal interface resistance as well as basic depth information. The thermal expansion of the clamped gold film can be calibrated to absolute temperature change and effects of plastic deformation are discriminated. The method is demonstrated on two extreme examples of phononic barriers, isotopically modulated silicon multilayers with very small acoustic impedance mismatch and silicon-molybdenum multilayers, which show a high resistivity.

We present the application of single-shot multicontrast X-ray imaging with an inverted Hartmann mask to the time-resolved in situ visualization of chemical reaction products. The real-time monitoring of an illustrative chemical reaction indicated the formation of the precipitate by the absorption, differential phase, and scattering contrast images obtained from a single projection. Through these contrast channels, the formation of the precipitate along the mixing line of the reagents, the border between the solid and the solution, and the presence of the scattering structures of 100–200 nm sizes were observed. The measurements were performed in a flexible and robust setup, which can be tailored to various imaging applications at different time scales.

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